Project Summary/Abstract: Recent terrorist incidents remind us of the need for coordinated and effective responses to improve patient safety, victim survival, and the safety of first responders. Current simulations to train for situations like this generally include paper cases or analog recreation of mass casualty incidents (MCI). These simulations typically are comprised of teams of emergency responders triaging a combination of moulaged manikins and actors. The drills can be made more realistic by adding noise, smoke, sirens and other distractions like media and police presence depending on the resources available. Although these simulations may be effective, they are expensive to construct and maintain, are often not duplicable by other institutions, vary in their degree of reality and fidelity simulating the actual event, and rely fully on human evaluators to assess the participants. Virtual reality (VR) offers the opportunity to simulate highly immersive recreations of real life situations. VR provides an excellent approach for simulating complex scenarios such as mass casualty incidents, allowing students, staff, and first responders the ability to train in environments that more closely mimic real-life situations. Recent improvements in VR technology, hardware, and software now enable the creation of realistic, highly immersive simulations that can be utilized by a wide variety of trainees and institutions in a cost-effective manner. VR systems can be designed to include real-time, automated, unbiased assessment of whether educational or training objectives are being met. VR systems also enable replay ability at a lesser cost than analog scenario simulations of MCI. Finally, systems can be designed to provide different levels of difficulty or interchangeable scenarios using procedural variations. The overall goal of the present proposal is to evaluate virtual reality as a training and assessment tool for simulating a mass casualty incident following a subway bombing, and assess the effectiveness of these simulations compared to existing analog approaches. The proposal describes the design, development, evaluation, assessment, packaging, and deployment of a highly immersive virtual reality simulation that can be utilized by a wide variety of trainees at universities, medical schools, training programs, and local fire, safety, and EMS departments.